I have had one episode where the clutch pedal did not return all the way to the full out position though it the clutch was fully engaged. I resolved it self when I noticed this lack of full return and pulled it out with my foot. Most recently it seemed like the clutch pedal was stuck all the way down on the floor just momentarily, nothing major and now all seems okay. I won't go and ask until the problem can be reproduced for the dealer. Curious if anyone has noted anything similar. So far the forum has saved me several trips. Thanks

 

We are hearing more and more about this problem. I suspect it is a situation where the "clutch throw" is too long, and because of that the clutch pedal goes to the floor and sticks there for an instant. Look at the thread started on 3/10/05 "C6 Clutch Adjustment". There is a simple way to adjust "air gap" and "clutch throw". It is an old trick used by rodders in the 1960's. It can't hurt to try it. I don't have my C6 yet but if I had your problem I know what I would do. Won't cost you a penny and can be done in a few minutes. I am curious if it works on the C6, it worked on the muscle cars in the 1970's.

 

Same thing here...seems to only occur when the car is cold....once it warms up it is gone.

 

Thanks DANNOV, i havent had any more problems but will read the 3/10 threat when I get a chance in case more problems are noted.

 

I noticed my clutch pedal not returning all the way to the up postition but it never stopped the car and it fixed itself when it warmed up so I guess it's not really a problem. It's only a problem when the tow truck has to be called.

 

Clutch pedals sticking to the floor is certainly not an issue peculiar to the Corvette but more a "diaphram clutch" issue in general. It usually occurs when the clutch mechanism is overcentered at higher RPM. In the "Old Days" when we still had positive mechanical linkage, we used to adjust the linkage so as to attain no more than 0.050" release clearance between the pressure plate and the disc (with the pedal fully depressed) as measured through an access hole in the bottom of the bellhousing. I would imagine some sort of pedal stop might do the same with the current hydraulic units.

 

I think this man is correct! It is a matter of adjusting the "air space" between friction surface and flywheel. In the old days there were ways to adjust this, but not anymore with hydraulic units. Some form of pedal stop that prevents the clutch pedal from going completely to the floor would cure the problem. Some BMW models have such a stop.
I might also add that since the addition of the clutch/starter interlock switch several years ago as a safety device, the "clutch throw" has typically become much longer. This was probably done to prevent starting problems by insuring that the clutch/starter switch was fully activated when the clutch pedal was depressed. But that longer "clutch throw" results in a wider "air gap" and creates the "overcentering" problem described by Sparky65.
"Clutch throw" is the dead space or "play" from where the clutch pedal is pressed to the floor to where the clutch engages as the pedal is released. Reduce that dead space and you probably cure the problem. I have always done this on all my cars to adjust the clutch feel to my personal liking.
One additional point that no one has mentioned is that this problem could get worse as your clutch wears. This is because the hydraulic clutch is self adjusting, i.e. and you have the same clutch pedal play despite wear on the clutch plate friction surface. I may be wrong, but I believe this automatic adjustment will cause the "air space" between the friction plate and flywheel to become wider as the clutch wears. This may create an even greater "overcentering" problem.
If you do a Google search on "clutch play" and "clutch air space", you will find a few references that explain the mechanics.

 

In those 'old days' we put something under the carpet, where the clutch pedal touches the carpet, to shorten the throw. Or, attach something to the back of the clutch pedal to make it contact the carpet earlier. You just have to make sure the clutch goes far enough forward to let you engage the starter switch.

 

I just buildup the space under the carpet with several pieces of indoor/outdoor carpet. This carpet is thin and you can keep adding pieces, one over the other, until you get the clutch throw you desire. If you go too far you will discover the clutch/starter interlock switch will not function.

 

I haven't looked, the car is in for a new battery today. Can you pull the carpet down from its top edge? How do you keep the carpet pieces you put in there from moving?
I was thinking about bolting some wood to both sides of the clutch pedal. The back side to do as the above. The front side to shorten the distance I have to reach the pedal. I'd like to move my seat back a little.

 

My question here is why do most C6's not have a problem but a few do? There must be a better way to fix this than stuffing blocks under the carpet. What about disconnecting the clutch cable above the clutch pedal and putting a little wire loop in there to lengthen the cable a little?

Mike

 

When clutches had cables you could normally make such an adjustment, but today there are no cables, all hydaulic. I don't think there is a way to adjust "air gap" or "clutch throw" on a C6 without resorting to what appears to be a "clunky" solution. I don't have my C6 yet, should get it on Monday, so I have not experienced the problem in question. Also, I have not seen any manuals for the C6 that show the clutch mechanism. But, I have experienced the same problem on other cars.
If the solution with blocks or padding under the carpet is too primative; then, you could weld a metal piece to the clutch pedal with a threaded rod to adjust the clutch throw. Drag racers who race older Mustangs have used this modification. This mod is on the Web, in one of the Mustang forums, you should be able to find it by searching. As I mentioned earlier, some BMW's have pad on a threaded rod under the clutch pedal. The rod is attached to the floor and you can screw the pad in and out to adjust clutch throw.
Why do some C6's have the problem and others don't? Who knows, we have many C6 owners with stange and unique problems, e.g. crankshaft pulley problem.
If I experience a clutch problem with my C6, I intend to remedy the situation using one of the "clunky" methods or devise a variation of the BMW system. I suspect that the problem will not get better over time, just worst. If after 5000 miles you take it back to the dealer with a clutch problem, they could claim the clutch and related parts are "wear items", like brake pads. It might be difficult to get a warranty repair.

 

I'm curious about the cases where the clutch doesn't come up, is it only at higher RPMs or does it happen even when the vehicle is off?

 

It only happened to me once, at high rpms getting on it, a few months ago.

 

Tonight I got under the steering wheel and looked around.
You cannot build up the carpet to any effect, as there is a special 'nubbin' on the clutch pedal arm, that engages a plastic switch in back, when the clutch pedal is fully depressed. The pedal, itself never gets close enough to the floorboard.
I did two things tonight.
First, I clamped a small metal bracket to that 'nubbin' in a reverse fashion. The head of the bolt that holds this piece on, now sticks out backward about a centimeter and will make contact with the plastic switch. It has eliminated about one centimeter of travel before the clutch engages. It doesn't sound like much, but the clutch definitely engages sooner now. (It also still completely disengages, and the starter works) It just may be smoother. There is very little play left to work with.
Second, I built up the clutch pedal by putting 4 large bolts right through the 4 pedal holes, tightening them down with bolts on the backside of the pedal. The heads of these bolts effectively bring the pedal about another centimeter closer to the driver. The bolts also give a better grip, which may or may not turn out to be good. So far, though, so good.
Being rather short (5-7) these mods seem to helping in the right direction. I have been trying to move my seat back. I had an automatic C5, and got used to sitting farther back. With the MN6 C6 I had to come closer to the steering wheel because of the long clutch pedal reach. That brought me too close to the shifter for my comfort. I'm now back a good inch, so at least it's helping.
I do believe that the shorter clutch throw is the way to go, and it just might make launches easier. So far, I've only driven a few miles with the mod.

I uploaded some pictures of the bracket I used, and the modded clutch pedal and arm, and they should be approved soon:

http://forums.corvetteforum.com/phot...check=0&page=1

 

Apparently this is a problem in C5s as well. Some have removed a spring that is used to 'help' reduce the effort to depress the clutch. This has helped them a lot, as now the clutch has less tendancy to stick to the floor, but it takes more effort to depress it. I don't know if the C6 has this helper spring or not - I'm quite disappointed GM didn't fix this problem when changing models - that is sad!

 

Hoonose
That metal bracket in photo #1, is that something you fabricated or is it already on the clutch pedal? I am operating under a handicap here because I won't get my car until Monday.
But it appears that you are reducing the clutch throw by shortening the distance between the clutch pedal and the interlock switch. In a lot of cars the pedal just goes to the floor and stops there, but in the case of the C6 it seems like the pedal stops when the interlock switch is depressed. If that is the case it should be easy to adjust clutch throw.

 

That little bracket is something I found lying around in my shop. In fact I found a bunch of them, but I don't remember what they were for!
By attaching them to the clutch arm, backwards, the bolt is what sticks out and engages that switch early. This shortens the throw.

 

That little bracket is something I found lying around in my shop. In fact I found a bunch of them, but I don't remember what they were for!
By attaching them to the clutch arm, backwards, the bolt is what sticks out and engages that switch early. This shortens the throw.

I drove around more today, and like the shorter throw. There's one light I get stopped at, daily, that is on an uphill. It seems easier and smoother starting there with this change. Maybe I'm paying more attention, but before, I commonly used the parking brake to hold my position there, before easing out the clutch and starting back uphill.

 

That is a clean and easy way to adjust clutch throw. Anyone who has a problem with the clutch action should take heed. It is surprising how even small changes in the clutch throw can make the car much smoother off the line. There are not many people who know that such an adjustment is even possible. You took the basic idea and made it work. Nice!